Twilight / sunset landscape

The attribution to Narcisse-Virgile Diaz de la Peña has been questioned. Opinions were sought by Bryony Dawkes from the National Gallery and the Ashmolean. Sarah Herring and Chris Rioppelle (National Gallery) could find no reason why it shouldn't be attributed to Diaz. However Colin Harrison (Ashmolean), a Diaz expert, considered ''I confess I do not know this painting, but it has only a very loose relationship with Diaz's work. Of course, when it was bequeathed to Aberystwyth, he was one of the most expensive of modern artists, and there were a great many imitations and downright fakes. However, your painting is really so slight as to make any attribution at all difficult. I am affraid 'French School' is as far as I would go''